1. Field of the Invention
The invention relates in general to a multimedia system, and more particularly to a multimedia system capable of carrying out data transmission between a remote client device and a multimedia access device on a local network without punching through the network address translation (NAT) or firewall device of the local network.
2. Description of the Related Art
In the present ages, network masquerading techniques have been well developed and applied for hiding an entire local network addresses behind a single public address. Generally, a network address translation (NAT) or firewall device is used in conjunction with the network masquerading. The NAT/firewall device is run on a router to map addresses behind the router to a single destination address, using different ports. Thus, for stations on the public network, it appears that the IP packets are sent from the router.
However, the networks apply NAT/firewall techniques have some undesired problems. For example, when two computers, which are both behind their NAT/firewall devices, try to connect with each other, neither of them will be able to do so because no address mapping scheme exists. This is a problem with voice communication, peer to peer games, or games where your client device operates as the host device and is positioned behind a NAT/firewall device.
Conventionally, users have to setup a port mapping scheme i.e. scheme for punch through the NAT/firewall devices on their routers, so as to solve the up mentioned situation. However, this is a challenging task and inconvenient situation for the users. Thus, how to develop a way to fix the up-mentioned problem is a prominent goal for the industries.